If the gross distribution was $20,000 and they withheld the default 10%, $2,000, the withholding will only be sufficient to cover the penalty. The $20,000 will be added to your other taxable income, so this distribution will likely increase the amount of your income tax liability and you may have a balance due. But as TurboTaxMinhT indicated, you won't know until you complete your tax return. Your tax return will show your early distribution penalty on Form 1040 line 59, your overall tax liability including the penalty on line 63 and the $2,000 of tax withholding with be included as a credit on line 64 to be subtracted from the amount on line 63.
